The pyorrhea alveolaris is one of typical dental diseases as well as dental caries, and is not a disease of a tooth itself but rather is a chronic disease which occurs in peripheral tissues for, supporting a tooth, in which the alveolar bone which is a part of the jaw bone is absorbed and destroyed, and a series of tissues which connects the bone and the tooth is destroyed to produce suppuration. Consequently, such symptoms are finally shown in many cases that pus appears and the tooth becomes unsteady. As initial symptons, an itching sensation of the gums (tissue), hemorrhaging and the like take place.
As the cause of pyorrhea alveolaris are listed many ones, among which such a case is considered to be dominant as particularly important one that an inflamation is caused by stimulation to the gums due to the tartar formed by depositing of lime salts in the saliva on dental plaques stuck on the tooth, to which suppuration bacteria infect to produce pyorrhea alveolaris. Namely, as in the case of dental caries, it is considered also in the falling ill and the proceeding process of pyorrhea alveolaris that infection by bacteria is an important factor.
Some trials have been done in which attention is given to the relation between infectious microorganisms and diseases of the oral cavity such as pyorrhea alveolaris, and the growth of infectious microorganisms is restricted or inhibited, thereby prevention or restriction of such diseases of the oral cavity is intended to follow.
When the growth of infectious microorganisms is intended to be restricted or inhibited in the oral cavity, for example, by using some active substance, it is desirable for the active substance to satisfy such conditions that it has no toxicity, it has an effective activity against microorganisms, it has no taste or odor or has good taste, it can easily be used in a relatively small amount, it has good stability, it is advantageous from a view of cost and the like. According to these viewpoints, it has been carried out in order to prevent or restrict diseases of the oral cavity such as pyorrhea alveolaris and dental caries, for example, that lysozyme is added to foods such as chewing gums and the like.
Lysozyme exists also in the oral cavity especially as an enzyme of saliva which is known to act against bacteria to destroy it. This is caused owing to the activity of the enzyme to decompose polysaccharide in the bacterial membrane of the bacteria. In addition, lysozyme is known to have the anti-bacterial action as well as the anti-viral action, the hemostasis action, the anti-inflammatory action and the like.
As one of trials for applying lysozyme to compositions for the oral cavity can be exemplified a production method of a chewing gum composition for preventing pyorrhea alveolaris and dental caries which has been disclosed by the present applicant in the Japanese Patent Publication No. 49-32066. In this publication the present applicant has disclosed a production method of a chewing gum composition for preventing pyorrhea alveolaris and dental caries characterized in that a chewing gum base obtained by a usual means is heated to not more than 60.degree. C., to which a chewing gum additive is added to mix by kneading, and lysozyme is added so as to be contained by 1 to 60 mg units per one g of a chewing gum product.
The chewing gum composition obtained according to this technology is sufficiently effective to prevent pyorrhea alveolaris and dental caries, while as the result of further investigation of the present inventors, it has been found that a distinct natural active ingredient is formulated in combination with lysozyme as a chewing gum, thereby a chewing gum which may more effectively prevent or restrict especially pyorrhea alveolaris can be realized to complete the present invention.